The M388 Davy Crockett, a short-ranged recoilless gun, to firing the M388 nuclear projectile. Its production began in 1956, tested between 1962 and 1968, but deployed with US Army forces from 1961 to 1971.

The entire projectile weighed 76 pounds and was 2 feet, 6 inches long with a diameter of 11 inches. The W54 warhead portion encased in the projectile weighed 51 pounds. The weapon had an automatic lethal radiation exposure radius of 10,000 rem out to164 yards (150m) at the blast site and a delayed fatal dose of 600 rem within 150 yards (137.16m) of the blast center - of course this was all dependent on wind direction.

The world's largest bombard by caliber: Tsar Cannon, created in 1586 by Andrei Chokhov, now displayed in the Moscow Kremlin. The 19.5 ft (5.94 m) long weapon has a caliber of 890 mm.

The most powerful thermonuclear weapon ever detonated: the Tsar Bomb, released over the Mityushikha Bay testing range, Novaya Zemlya archipelago, Soviet Union, on October 30, 1961. It had the yield of 50-58 megatons of TNT, made a fireball, about 5 miles (8 km) in diameter and totally destructed everything in a circle 44 miles (70 km) in diameter.

A .950-caliber rifle, the largest centerfire rifle ever made with the biggest cartridges, developed by SSK Industries. Only three were made.

Typhoon-class nuclear submarines, (also known as the Project 941 or Akula) the largest class of submarines ever built. Six of them were launched, between 1980 and 1988, but now all of them are retired, and three were scrapped.

All six ships were 574.15 ft (175 m) in length.

(via Dmitry Lovetsky/AP)

The largest-calibre rifled weapon ever used, with the heaviest artillery shells: Schwerer Gustav and Dora, two railway guns weighed 1350 tons, designed and built by Krupp in the late 1930s to destroy the main forts of the Maginot Line with their seven ton (800 mm caliber) shells from a distance of 29 miles (47 km)

Gustav was captured by American soldiers, but Dora was destroyed by the Wehrmacht in 1945 to avoid capture by the Red Army.

The .600 Nitro Express Zeliska revolver, by the Austrian Pfeiffer Waffen, the largest handgun in the world, weighing 13.230 lb (6.001 kg), producing a muzzle energy of 7,591 foot pounds. It works with .600 Nitro Express cartridges, which were widely used for killing elephants in the early 20th century.

Project Babylon, a supergun project of Saddam Hussein, began in 1988, but halted two years later, when the produced sections were seized in transit, and the Iraqi parts were destroyed by the UN in 1991.

Two Big Babylons would have 512 ft (156 m) long barrels, and weigh about 2,100 tonnes each, intended to shoot projectiles into orbit.